In vivo optical coherence tomography detection of differences in regional large airway smoke inhalation induced injury in a rabbit model

Abstract

Smoke inhalation injury causes acute airway injury that may result in airway compromise with significant morbidity and mortality. We investigate the ability of high resolution endobronchial optical coherence tomography (OCT) to obtain real-time images for quantitatively assessing regional differences between upper tracheal versus lower tracheal and bronchial airway injury responses to smoke inhalation in vivo using a prototype spectral domain (SLD)-OCT system we constructed, and flexible fiber optic probes. 33 New Zealand White rabbits are intubated and mechanically ventilated. The treatment groups are exposed to inhaled smoke. The OCT probe is introduced through the endotracheal tube and maintained in place for 5 to 6 h. Images of airway mucosa and submucosa are obtained at baseline and at specified intervals postexpo-sure. Starting within less than 15 min after smoke inhalation, there is significant airway thickening in the smoke-exposed animals. This is maintained over 5 h of imaging studies. The lower tracheal airway changes, correlating closely with carboxyhemoglobin levels, are much greater than upper tracheal changes. Significant differences are seen in lower trachea and bronchi after acute smoke inhalation compared to upper trachea as measured in vivo by minimally invasive OCT. OCT is capable of quantitatively detecting regional changes in airway swelling following inhalation injury.

Investigating in vivo airway wall mechanics during tidal breathing with optical coherence tomography

“…The animals (male adult New Zealand White, 4 to 4.5 kg, Western Oregon Rabbit Co. Philomath, Oregon) were anesthetized with a ketamine-xylazine mixture, intubated with a 3.5 mm endotracheal tube, and imaged with our OCT system as described above and previously. 11,15,16 All methods were approved by the Institutional Animal Care and Use Committee at the University of California, Irvine (Protocol No. 2007-2754).…”

“…Endoscopic probes have been developed for many organs, allowing imaging of the blood vessels, esophagus, urethra, and airways with a resolution previously only available via biopsy and histological preparation. [14][15][16][17][18][19][20][21] Recently developed Fourier-domain OCT techniques maintain the same spatial resolution while offering video-frame rates (up to 100 frames/s). 20,21 Furthermore, unlike ultrasound, OCT can be used in noncontact modes and in air-filled lumens, such as the airways.…”

Optical imaging of subacute airway remodeling and adipose stem cell engraftment after airway injury

“…Increased thickening of basement membrane according to the epithelial thickening was apparent with following OCT monitoring. In several studies, the extent of injury has been quantitatively measured with this spectral-domain OCT system [13][14][15]. In this study, we first measured thickness of the basement membrane in injured tracheas.…”

Automatic airway wall segmentation and thickness measurement for long-range optical coherence tomography images

“…As a nonionizing, non-invasive medical imaging modality, optical coherence tomography (OCT) has been used to perform high resolution, cross-sectional imaging of biological tissues. Previous studies [6][7][8][9][10][11] have demonstrated the flexibility of OCT to image the airways of different animals in vivo. Among them, the Fourier domain long-range swept source OCT (LR-SSOCT) exhibits higher sensitivity, faster imaging speed and an extended imaging range compared to conventional OCT systems.…”